User:Rdx

Nintendo 3DS

Developer	Nintendo
Type	Handheld game console
Generation	Eighth generation
Release date	2011
Discontinued	2020
Predecessor	Nintendo DSi
Emulated	✓

The Nintendo 3DS is an eighth-generation handheld game console by Nintendo, released on March 27, 2011 for $249. The original model and the 2DS had a dual-core ARM11 MPCore at 268 MHz and a single-core ARM9, 128MB of RAM and 6MB of VRAM, and a DMP PICA200 GPU. The New 3DS and New 2DS XL models upgrade this to an 804 MHz quad-core ARM11 and 256MB of RAM, along with an extra pair of shoulder buttons and a right analogue stick.

The most notable feature of this console is the use of autostereoscopic (glasses-free) 3D, which can be configured using a slider. This was omitted on the cost-reduced 2DS and New 2DS XL models, which was released due to eye health concerns with children whom Nintendo advised not to use the 3DS's stereoscopic mode (though it is speculated that said advisories were more for liability reasons in case of a health-related lawsuit).

Emulators

Name	Platform(s)	Latest Version	Open-Source	Libretro Core	Active	Recommended
PC / x86
Citra		Nightly	✓	✓	✓	✓
Corgi3DS		git	✓	✗	✗	✗
3dmoo		git	✓	✗	✗	✗
TronDS		1.0.0.5	✗	✗	✗	✗
LemonLime		git	✓	✗	✗	✗
Mobile / ARM
Citra-MMJ		git	✓	✗	✓	~ (WIP)
Citra		Beta 15 git	✓	✗	✓	~

Comparisons

Citra

An open-source Nintendo 3DS emulator made by experienced emulator developers. The devs insist that it's still experimental, but as of mid-2019 around half of all games are fully playable with minor or no issues. An official Android version was released in May of 2020.

3dmoo

Another open-source Nintendo 3DS emulator, made by experienced developers in the DS hacking scene. It was released shortly after Citra and received similar progress for a few months, but was eventually aborted by its authors after a while.

TronDS

A closed-source Nintendo 3DS emulator, presumably made by the iDeaS author. Little is known about it other than that it can run simple homebrew. It cannot be used for playing games.

Corgi3DS

An unique 3DS emulator designed for macOS systems. Its GitHub activity started on May 5, 2019. Main programmer is a self-proclaimed dog lover and has previously created CorgiDS and DobieStation, though the former seemed to be abandoned. Corgi3DS is mainly indigenous but the preliminary Wi-Fi code was ported from melonDS' code.(project on a indefinite hiatus, PSI said this about the matter "Haven't worked on it in several months, it's basically a hobby project of mine that I touch when I feel the urge").

Emulation issues

Citra currently can't emulate any of the 3DS's online features aside from LAN multiplayer. It can't connect to Nintendo's servers but users can create rooms and play through the internet.

Corgi3ds currently can't run any game without heavy stuttering.

Citra emulates the home menu although you can't launch anything on it.

Game images

3DS vs. CIA

There are two big types of 3DS game images currently:

NCSD-type

Includes .CCI (CTR Cart Image), aka .3DS - data on physical carts, can be executed right off the bat, not used much since no one bothered to develop a CFW solution to load them yet (besides converting them to CIA) and only overpriced flashcarts (Gateway/Sky3DS) can load them.

NCCH-type

Includes .CIA (CTR Importable Archive) and .CXI - installers that unpack game data to the SD card or the 3DS NAND memory. Some homebrew apps (FBI, DevMenu) can install CIA files on 3DS systems with CFW installed. Digital games are often distributed as CIAs.

• Note that CTR (Citrus) is the internal code names for the 3DS.

Due to one format being so far restricted to overpriced flashcarts and the very slow Citra development (meaning playing on a real 3DS is still the preferred way to go), the CIA format is preferred in many sharing websites, downloader tools and even tools to dump your own games.

However, converting a CIA image to 3DS format (and vice-versa) is still possible with no loss of content. Read the Encryption section below for a guide.

Some outdated dumping utilities intended for use with Citra (like braindump) produce damaged decrypted 3DS images that can't be easily converted back. No known solution exists so far to fix those dumps.

Encryption

Most dumps online are also encrypted. This encryption poses no problem for playing game images on a real 3DS since it can deal with that encryption with internal keys included in the bootrom, but becomes a problem when trying to emulate them on PC. Citra requires additional encryption keys to play encrypted games. If you want to play encrypted games on Citra without these keys, you'll have to convert your game images to the decrypted format.

Formerly, decrypting those ROMs used to require real 3DS hardware (bafflingly enough, Citra devs still ask users to do this even nowadays). It required files generated by a real 3DS called xorpads unique to that game version, using the encryption engine within the 3DS. After this part, these xorpads (which are big) can be used with PC tools (or other 3DS-based homebrew) to produce the decrypted game image. After that, some 3DS homebrew (Decrypt9, GodMode9) included tools to directly convert encrypted images to decrypted images with a single button press, but those still require a real 3DS.

The game changer was the sighax exploit, allowing to dump the 3DS bootrom which includes these encryption keys. This file can be downloaded from the Emulator Files page. You can then use a program like fuse-3ds to decrypt games using this file. Simply place boot9.bin in the same folder, run the program, mount the encrypted .cia or .3ds, and find the decrypted.cxi file inside (usually in the first folder). Citra should be able to load this file without issues.

Due to these keys being available, Citra can now play encrypted games (3ds or CIA) without decrypting them. Read this page [1]. Then, go to this reddit page and copy the code from second comment (credit floppydoppy2) [2]. Copy it and make a new .TXT file named 'aes_keys.txt' Place this txt file in the sysdata folder of Citra's user directory. This key file is already included in the 3DS Shared Data download in the Emulator Files page.